mark.lin@Eng 1998-05-18

If you call Transferable.isDataFlavorSupported() with a custom dataFlavor and there is a X11Selection currently on the system clipboard, you get a null pointer exception. This only occurs on Solaris, not NT.

java.lang.NullPointerException
        at sun.awt.motif.X11Selection.isDataFlavorSupported(X11Selection.java:223)
        at TestClip.<init>(TestClip.java:39)
        at TestClip.main(TestClip.java:49)

Attached is code to reproduce this bug.

/**
 * This program demonstrates a null pointer exception bug that occurs whenever
 * you call Transferable.isFlavorSupported() using a custom dataflavor and
 * there is currently a X11Selection transfer on the system clipboard.
 * This bug only occurs on Solaris.
 * Here is how you run it:
 * Before starting the program, place text onto the system clipboard through
 * some third party application (ie. copy some text from xemacs). Now start
 * the program by typing 'java TestClip'. Note that you get:
 * java.lang.NullPointerException
 * at sun.awt.motif.X11Selection.isDataFlavorSupported(X11Selection.java:223)
 * at TestClip.<init>(TestClip.java:20)
 * at TestClip.main(TestClip.java:26)
 */

import java.lang.*;
import java.io.*;
import java.awt.*;
import java.awt.datatransfer.*;

public class TestClip extends Object {

    class MyFlavor extends Object implements Serializable {
        // Stub class needed in order to define the data flavor type
    }

    public TestClip () {
        // Create an arbitrary dataflavor
        DataFlavor myFlavor = new DataFlavor(MyFlavor.class, "TestClip");
        // Get the system clipboard
        Clipboard theClipboard =
            Toolkit.getDefaultToolkit().getSystemClipboard();
        // Get the current contents of the clipboard
        Transferable theTransfer = theClipboard.getContents(this);

        // See if the flavor is supported. This will result in a null
        // pointer exception on Solaris, but not NT
        boolean isSupported = theTransfer.isDataFlavorSupported(myFlavor);

        System.exit(1);

    }

    public static void main(String argv[]) {
        // Create a new TestClip class
        new TestClip();
    }

}